Photographic film processing is accomplished by immersing undeveloped film in a number of liquid solutions in a pre-determined order. These steps include developing, bleaching, fixing, rinsing, etc., and it has long been conventional to automate film processing by providing a series of adjacent open-topped tanks in a housing through which long strips of film are sequentially transported by a film transport system.
A number of systems have been devised for transporting film through such a series of tanks. For example, U.S. Pat. No. 4,739,357 to Zielinski and U.S. Pat. No. 4,613,221 to Takase, et al, disclose film processors where one endless timing belt per tank is provided, each belt including projections for engaging apertures in a thin flexible film carrier card to advance a film strip attached to the card through the processing machine. While the use of a film carrier card as taught by these patents is generally advantageous, the use of multiple timing belts, one per tank, results in an unduly complicated construction, and transferring the card from belt to belt creates problems, particularly as noted in the Zielinski patent. Systems utilizing a single pair of spaced belt-like structures running in serpentine paths through all of the tanks have also been disclosed, as in U.S. Pat. No. 4,140,383 to Schmidt, U.S. Pat. No. 4,662,554 to Yamazaki et al, and U.S. Pat. No. 3,810,568 to Kwiaikowski et al. In these systems, the dual serpentine belting arrangement is an advantageous feature, but complicated attachment schemes requiring highly specialized film carriers are required.
Thus there presently exists a need for a film transport system which accommodates the use of a thin flexible film carrier card with a simplified dual serpentine belt arrangement.